Wisconsin, constituent state of the United States of America. Wisconsin was admitted to the union as the 30th state on May 29, 1848. One of the north-central states, it is bounded by the western portion of Lake Superior and the Upper Peninsula of Michigan to the north and by Lake Michigan to the east. The state of Illinois lies to the south, and Minnesota and Iowa lie to the west and southwest, respectively. The name Wisconsin is an Anglicized version of a French rendering of an Algonquin name, Meskousing, said to mean “this stream of red stone,” referring to the ... (100 of 7,200 words)